Do not use spaces in your answer. the measure of arc ps is

Hello from MrBillDoesMath!

129

Discussion:

Angle PAR =  Angle PAS +  Angle SAR    (*)

Angle PAR = 180  (a straight line has 180 degrees)

Substituting in (*) gives

180  = Angle PAS + Angle SAR

But Angle SAR = 51 (given)   =>

180 = Angle PAS + 51            => subtract 51 from both sides

Angle PAS = 180 - 81 = 129

Since PAS is a central angle, measure of the arc PS  = measure angle  PAS = 129

Note: I'm assuming that arc PS refers to the smaller arc, not arc PQS ( the larger arc). The problem statement is not clear on that point.

Thank you,

MrB

the correct answer is d

hope this

the answer is; biodiversity resulting from few ancestors

adaptive radiation occurs when a population is subjected to a large natural environment with spatial ecological variations. the parts of the population in the different ecologies begin to adapt to their local environments. due to non-random mating across the large populations, this causes the different populations from the large population to speciate within their local environments. they, therefore, diverge to different species sharing a common ancestor.